#include<iostream>
using namespace std;

class X {
       protected:
                    void fn() { cout << "In X::fn()\n"; } 
       public:
                    X() { cout << "In X::X()\n"; } 
                   virtual void print() { cout << "In X::print()\n"; fn(); } 
                   virtual void fnx() { cout << "In X::fnx()\n"; }
};

class Y : protected X { // Inheritance of Y from X
        public:
                Y() { cout << "In Y::Y()\n"; } 
                virtual void print() { cout << "In Y::print()\n"; fn(); } 
                virtual void fny() { cout << "In Y::fny()\n"; }
};

class Z : public Y { // Inheritance of Z from Y
        public:
                 Z() { cout << "In Z::Z()\n"; } 
                 virtual void print() { cout << "In Z::print()\n"; fn(); } 
};

void foo1(X& obj) { obj.print(); } 
void foo2(Y& obj) { obj.print(); } 
void foo3(Z& obj) { obj.print(); } 
void foo4(X obj) { obj.print(); } 
 
int main() {
       X objx; 
       Y objy; 
       Z objz; 
       foo1(objx); 
       foo4(objx); 
       foo2(objy); 
       foo4(objy); // `X' is an inaccessible base of `Y' 
       foo3(objz); 
       foo4(objz); X' is an inaccessible base of `Z' 

return 0;}

foo3(objz)